Workaround Cinder "wishlist" bug 1255593 for multi-backend volume_clear

Cinder currently only applies the volume_clear setting from the DEFAULT
section of cinder.conf if you're using a single backend.

The Cinder team has determined this is a 'wishlist' item to propagate
volume_clear to each backend, but it does impact usability and
performance.

To improve the performance of running Tempest with multi-backends in the
gate, workaround the bug in devstack.

Related-Bug: #1255593

Change-Id: Ia0ff5422f53eeda9a3ac4336eefec3b9bdea6da2
Qemu emulator requires at least 128MB of memory to boot on ppc64

The default nano and micro flavors need more memory to boot on
ppc64. New flavors are 128MB and 256MB, respectively.
Trailing spaces removed, again.

Change-Id: Ic6740bda959754380982e67f753876dc6d984685
XenAPI:  Increase DomU's memory

Devstack has been increasing in complexity, and if we use too
much of our memory it can lead to fragmentation which in turn
causes a DomU error and a failure of random tests.

Change-Id: Ide9cc84625caed4e35a64a47ee1e92a6cd567651
Added keystone auth port to the nova config

Added the $KEYSTONE_AUTH_PORT to the keystone_authtoken
section of the create_nova_conf function.
This is required as without it nova doesn't communicate
to the keystone server. Generating an "Unauthorised (HTTP 401)"
page when acceesing /admin/.

Change-Id: Ibf4d9d1c21081a1e3de4ea765f4db6de5fbdb237
Merge "XenAPI:  Increase DomU's memory"
Merge "Workaround Cinder "wishlist" bug 1255593 for multi-backend volume_clear"
Merge "Qemu emulator requires at least 128MB of memory to boot on ppc64"
Merge "Added keystone auth port to the nova config"